The invention relates generally to a viewfinder for a camera and in particular to a viewfinder with an aiming aid that informs the photographer when the camera is improperly tilted relative to a subject to be photographed.
All cameras include a viewfinder for defining, i.e., framing, the area of a subject intended to be included in the picture.
When a camera is improperly tilted up, down, right or left relative to a subject to be photographed, a corresponding edge portion of the area of the subject intended to be included in the picture may be omitted. Unfortunately most viewfinders do not alert the photographer to this problem.
Prior art commonly-assigned U.S. Pat. No. 4,891,658 issued Jan. 2, 1990 and U.S. Pat. No. 4,893,141 issued Jan. 9, 1990 disclose solutions to the problem by providing a viewfinder with an aiming aid that informs the photographer when a camera is improperly tilted relative to a subject to be photographed. In the patents, a front aiming or target ring defines a front framing opening for aiming the camera at the subject. The front framing opening is optically aligned with a similar-shaped rear viewing opening. One views the subject by looking through the rear viewing opening to frame the aiming ring around the area of the subject intended to be included in the picture. When the camera is improperly tilted up, down, right or left relative to the subject, the aiming ring blocks a corresponding edge portion of the area from one""s view through the rear viewing opening.
According to one aspect of the invention a viewfinder that informs the photographer when a camera is tilted relative to a subject to be photographed comprises:
a pair of front and rear openings optically aligned to view a subject through the two openings; and
a translucent element surrounding the front opening to permit a halo of light around the front opening which can be seen through the rear opening;
and wherein the rear opening is dimensioned sufficiently smaller than the front opening to prevent one from viewing through the rear opening various portions of the halo of light depending on whether the camera is tilted up, down, right or left, whereby one is alerted when the camera is tilted relative to a subject.
According to another aspect of the invention a method of alerting the photographer when a camera is tilted relative to a subject to be photographed comprises:
providing a halo of light around a front viewfinder opening in a camera which can be seen through a rear viewfinder opening in the camera when the camera is properly aimed at a subject, and
preventing one from viewing through the rear viewfinder opening various portions of the halo of light depending on whether the camera is tilted up, down, right or left relative to the subject, whereby one is alerted when the camera is improperly tilted relative to the subject.